This invention relates to agricultural material handling equipment and, more particularly, to a hydraulically operated bunk silo unloader which detachably connects to an agricultural vehicle having a flat bed trailer on which is carried a silage mixer box. The silo unloader mechanism detachably connects to the forward end of the vehicle and is operable via controls in the vehicle cab to comminute and transport silage from a stacked bunk silo bed into the silage mixer box.
Silage is typically deposited and allowed to cure outdoors in large horizontal bunk silos which can attain height, width and depth dimensions on the order of 10-15 feet or more. Bunk silos usually are confined on either side by a pair of vertical side walls and a back wall with the top and front thereof remaining open for the deposit and later retrieval of silage from the stack. As the stack is formed and allowed to cure, it becomes heavily packed and dense which presents handling difficulties at the time of gathering the silage from the stack. The silage must be removed from the stack and pulverized so that it may be mixed with other supplemental fodder for ultimate distribution to the animal feed stations.
Devices which comminute silage from horizontal silage stacks are known, some examples of which may be seen in the following U.S. patents:
U.S. Pat. No. 3,961,718 issued to Lucas on Jun. 8, 1976; PA1 U.S. Pat. No. 4,157,164 issued to Helm et al on Jun. 5, 1979; and PA1 U.S. Pat. No. 4,243,346 issued to Wolf on Jan. 6, 1981.
The Lucas device employs a vertically movable rotor 9 which discharges silage to a vertical conveyor 10 which deposits the silage into a trailer box 1.
The Helm et al device employs a vertically adjustable rotor 6 which dislodges and directs silage from a stack into a rotary beater 7 which breaks up large aggregations of forage and directs the same toward a conventional forage gathering device. The forage is then deposited on a housing 22 where it is urged toward a forage chopper 12 by an auger 23. The forage chopper 12 directs chopped forage to a blower 13 through a conveyor 14 to a trailing wagon 15 for later dispersal to livestock. The rotor head 6 is attached between a pair of arcuate-shaped booms which are hydraulically controlled by a pair of hydraulic rams 68.
Lastly, the Wolf device employs crank-operated rods which are angularly displaced of each other upon a pair of crankshafts for rotating movement thereon. The rods are generally vertically disposed and include longitudinally spaced work pieces thereon which are directed into the silage stack upon their respective downward strokes. Tines at the bottom of the rods push the silage detached by the work pieces backwards to a conveyor screw which delivers the silage to a blower unit for discharge to a feed trailer or the like.